Warren Diepraam, Waller County’s first assistant district attorney, at a news conference in Hempstead, Tex., on Thursday. “I have not seen any evidence that this is a homicide,” he said.CreditCreditIlana Panich-Linsman for The New York Times

HEMPSTEAD, Tex. — A county prosecutor in Texas said Thursday that an autopsy of Sandra Bland, who died in a jail cell here nearly two weeks ago after a minor traffic stop, concluded that her injuries were consistent with suicide, not homicide, a finding that underscored growing doubts that the jail did enough to monitor her.

Ms. Bland had told two jail intake workers on July 10 that she had tried last year to kill herself after losing a baby and told at least one of them that she had experienced bouts of depression. Yet they did not place her on a suicide watch or summon a mental health expert to evaluate her, steps national experts say should be standard practice. Nor did they follow other mandatory procedures aimed at protecting inmates at risk, state inspectors said last week.

Ms. Bland, a 28-year-old African-American who was moving to Hempstead from the Chicago area for a job at a local college, was found hanged from a plastic trash can liner in her cell on July 13. She was supposed to start her new job, at Prairie View A&M University, which was her alma mater, two days later.

On Thursday, the chairman of the State Senate committee that oversees Texas corrections said that the jail where she died, in Waller County outside Houston, had mishandled her case, and that state rules governing potentially suicidal inmates needed to be overhauled.

“When we lock somebody up, we have a responsibility to take care of them,” said Senator John Whitmire, a Houston Democrat and the longest-serving member of the Republican-dominated State Senate. “What I’ll be seeking is a review of jail standards, much more than we’ve ever done before. I personally believe it is long overdue.”

At a news conference, Warren Diepraam, Waller County’s first assistant district attorney, said that the autopsy showed that the condition of Ms. Bland’s head, neck and hands lacked any of the telltale signs of a violent struggle, and that the markings around her neck were consistent with suicide.

Video

A legal analysis of the arrest by Brian T. Encinia, a Texas state trooper, of Sandra Bland.

“I have not seen any evidence that this is a homicide,” Mr. Diepraam said. He added that there were some abrasions on her back that might have occurred during the arrest, and abrasions on her wrists consistent with being handcuffed.

Preliminary testing showed marijuana in her system, but he said the results of a more accurate test were still pending.

Prosecutors said they were releasing information from the autopsy, conducted by the Harris County Institute of Forensic Sciences in Houston, because the case has drawn national attention and, in part, to dampen suspicions.

“We’re trying to be open in this investigation,” the Waller County district attorney, Elton Mathis, said at the news conference.

Friends of Ms. Bland and her suburban Chicago family have said they had no indication that she had sought to take her life, saying that she was ecstatic about her new job at the college. Her family has indicated that it will seek an independent autopsy to corroborate the findings of the one conducted by Texas officials.

Ms. Bland’s death came three days after a traffic stop for changing lanes without signaling mushroomed into a furious confrontation with a white Texas state trooper who threatened her with a stun gun, then handcuffed and arrested her. State public safety officials have said that the trooper, Brian T. Encinia, 30, violated police procedures in the confrontation, and he has been moved to a desk job while state and federal inquiries are underway.

Her death, like those of a number of other African-Americans who died after encounters with police officers, has set off a national outcry as well as deep suspicion among some critics, including her family, of the Texas authorities who are investigating it.

Image

A memorial for Sandra Bland on Thursday at the spot where she was arrested in Prairie View, Tex.CreditIlana Panich-Linsman for The New York Times

A screening form for “suicide and medical and mental impairments” completed when officials admitted Ms. Bland to the jail on July 10 indicates that she said she had tried to kill herself last year with pills after losing a child, had battled depression and was feeling depressed at the time she was entering the jail. But a second questionnaire prepared hours later says that Ms. Bland had not ever been depressed and was not feeling depressed at that moment, though it does note her attempted suicide.

Explaining the discrepancy, Mr. Mathis said, “They’re telling me they asked her those questions two different times, that she gave different answers the second time.”

The intake forms also said that Ms. Bland was taking an antiseizure medication, Keppra, for epilepsy. The drug comes with a warning label approved by the Food and Drug Administration that includes a long list of possible side effects, including depression, aggressive behavior and thoughts of suicide. It was unclear whether she had access to the drug while in jail.

During a news conference illustrated with photographs of Ms. Bland’s corpse, Mr. Diepraam said her body carried abrasions on the back and lacerations on the wrists that could have been suffered during her arrest, or later by handcuffs. But there was no sign of serious injuries, he said, and no cuts or bruises that might suggest she had fought in her jail cell to keep someone from killing her.

Examiners also found scars and scabs from about 30 cuts on Ms. Bland’s left forearm, which they said had probably occurred two to four weeks ago. Prosecutors declined to say definitively what caused them, but “in multiple instances I have seen, those injuries, they are consistent with self-inflicted wounds,” Mr. Diepraam said.

An initial toxicology test also indicated that Ms. Bland had recently smoked or eaten marijuana, Mr. Diepraam said. He noted that because traces of marijuana leave the body quickly, she had to have consumed it not long before she died, and he said it could have been used in the jail.

Inmates near Ms. Bland’s cell did not smell marijuana smoke, and the cell contained no evidence of the drug, he said. He raised the possibility that she could have ingested it right before the traffic stop to avoid being arrested for drug possession. Explaining why the information was relevant, he said, “It is a mood-altering substance and a mood amplifier.”

More extensive drug tests may shed more light on that question later, he said.

The Harris County Institute of Forensic Sciences is headed by the chief medical examiner, Dr. Luis A. Sanchez, a University of Massachusetts medical school graduate who joined the staff as a senior deputy in 2001 before becoming the top medical examiner in 2003. He was previously deputy and acting medical examiner in Washington and served as a liaison to the United States attorney’s office. Waller County officials said they asked Harris County to conduct the post-mortem inquiry because of inadequate medical facilities in Waller County.

Nearly two weeks after her death, it remains unclear why Ms. Bland was allowed to remain under minimal supervision despite telling her jailers that she was depressed and had tried to kill herself.

The rules governing inmates with medical and mental problems in Texas’ 245 county jails are basic and, some experts say, inadequate. Jails must give mental health training to workers who deal with inmates. They must screen new inmates for signs of mental illness. And they must have a policy for dealing with suicide risks. Within those broad outlines, individual jails can design their own procedures as long as they pass muster with regulators.

Ms. Bland was screened for mental illness twice in three hours after being brought to the jail, documents show. But despite disclosing depression and a previous suicide attempt during one of those screenings, she was never designated a risk and marked for closer supervision.

That decision is left to the intake clerks who interview new prisoners — employees who, under the plan that Waller County submitted to the state, were to receive two hours a year of training in recognizing and handling mentally ill inmates. But after Ms. Bland’s death, inspectors for the Texas Commission on Jail Standards found that Waller County could not prove that its employees had received the training.

State regulations require that jail employees conduct a face-to-face inspection of each prisoner no less than every hour. Inmates who are deemed at risk — of assault, say, or of bizarre behavior — are seen no less than once every 30 minutes, and can even be placed under constant supervision if a doctor orders it.

In Waller County, state inspectors found, jailers did not even meet the minimum requirement of a personal inspection once an hour. Inspectors cited the jail for the same violation in 2012, after another inmate hanged himself in his cell with a bedsheet.

State Senator Whitmire said in an interview that the jail had made “a huge mistake” both by failing to order a suicide watch on Ms. Bland and by leaving a trash bag that could be used as a noose in the cell.

“If they had not had the trash in there with the plastic liner,” he said, “we would not be having this conversation.”

Mr. Mathis, the district attorney, noted that Ms. Bland also had a bedsheet. “We need to take the most precautions possible,” he said. “I do wish she would have been on a suicide watch. We all do.”

In an interview Wednesday, the Waller County sheriff, R. Glenn Smith, said that although Ms. Bland had told two intake workers she had attempted suicide last year — and also told one of them that she was feeling depressed at that moment — jail workers felt that her behavior was “just normal.”

On Thursday, LaVaughn Mosley, who had known Ms. Bland since college, said he had been among the last people to talk to her. An aspiring dietitian, Ms. Bland had driven to Texas from Chicago to interview on July 9 for a job involving a study of weight at Prairie View A&M.

She got the job that day and was ecstatic. She was to start the next week. But the next evening, she called Mr. Mosley from the jail and “told me she was going to press charges,” he said. They traded missed calls over the weekend as her family struggled to raise money to pay her bail. By Monday, she was dead.

Mr. Mosley said he remained in disbelief. “You don’t drive 16 hours, have the interview, get the job, get all excited and then kill yourself,” he said.

Correction:July 23, 2015

An earlier version of this article misstated the charge on which Sandra Bland was held. It was assaulting a public servant, not resisting arrest.

David Montgomery reported from Hempstead, and Michael Wines from New York. Sharon LaFraniere contributed reporting from Hempstead, Mitch Smith from Chicago and Gina Kolata from New York.

A version of this article appears in print on , on Page A1 of the New York edition with the headline: Texas Autopsy Is Said to Point Toward Suicide. Order Reprints | Today’s Paper | Subscribe